Department of Nephrology, Huadu District People's Hospital of Guangzhou, Southern Medical University, Guangzhou, China.
J Cell Biochem. 2020 Jan;121(1):621-631. doi: 10.1002/jcb.29307. Epub 2019 Aug 29.
Podocyte apoptosis importantly contributes to various kidney diseases. Long noncoding RNAs Colon cancer-associated transcript-1 (CCAT-1) has been demonstrated for a critical role in cell proliferation. In the present study, the relationship between CCAT1 and popdocyte impairment, and the underlying mechanism was investigated. Podocytes were isolated from mice and then treated with tumor necrosis factor-α to simulate podocyte injury. After developed CCAT1 overexpression or knockdown, cell viabilities were determined with the CCK-8 assay, apoptosis was examined with Flow cytometry, the autophagy was observed by Western blot. Furthermore, phosphorylated PI3K and Akt expressions were examined. We found that after CCAT1 overexpression, the cell viability was significantly increased, apoptosis was significantly decreased, and autophagy was significantly inhibited, which was indicated by induced P62, LC3B-I and decreased LC3B-II. In addition, CCAT1 overexpression induced the levels of phosphorylated PI3K and Akt. With Rap treatment, these effects by CCAT1 were reversed. Furthermore, the results contrary to the effects by CCAT1 overexpression were presented after CCAT1 knockdown, and this was inhibited by 3-MA. Taken together, our results suggested that CCAT1 induction critically participated in apoptosis inhibition in podocytes through autophagy inhibition via increasing PI3K/Akt signaling. This might act as a promising therapeutic intervention for renal diseases associated with podocyte apoptosis.
足细胞凋亡在各种肾脏疾病中起着重要作用。长链非编码 RNA 结肠癌相关转录本-1（CCAT-1）已被证明在细胞增殖中起着关键作用。本研究探讨了 CCAT1 与足细胞损伤的关系及其潜在机制。从小鼠中分离出足细胞，然后用肿瘤坏死因子-α处理以模拟足细胞损伤。在进行 CCAT1 过表达或敲低后，用 CCK-8 测定法测定细胞活力，用流式细胞术检测细胞凋亡，用 Western blot 观察自噬。此外，还检测了磷酸化 PI3K 和 Akt 的表达。我们发现，CCAT1 过表达后，细胞活力明显增加，凋亡明显减少，自噬明显受到抑制，这表现为 P62、LC3B-I 的诱导和 LC3B-II 的减少。此外，CCAT1 过表达诱导了磷酸化 PI3K 和 Akt 的水平。用 Rap 处理后，CCAT1 的这些作用被逆转。此外，在 CCAT1 敲低后，出现了与 CCAT1 过表达相反的效果，而 3-MA 抑制了这种效果。综上所述，我们的结果表明，CCAT1 通过增加 PI3K/Akt 信号通路抑制自噬，从而在足细胞中抑制凋亡。这可能成为与足细胞凋亡相关的肾脏疾病的一种有前途的治疗干预措施。
